DNA banking is a term used when people have a body sample such as blood or cheek cells or body tissue stored in a large commercial place of business or a research laboratory or a university or college or health institute or the like. The bank or the lab may subject the sample to an initial process such as DNA extraction before storage. The bank or laboratory may use special environmental storage and preservation conditions such as freezing or transformed cell lines. In addition, commercial institutions which offer banking of DNA and other genetic material might decide to discontinue the offering of this service, go out of business, be the target of a business takeover, change its array of services provided. These events have happened, and it leaves the owner of the DNA/genetic samples with the possibility of their samples being lost, transferred to a new place of storage, etc. Also, commercial institutions which store genetic material are subject to changing federal and state statutes which make it difficult for them to offer DNA banking. For example, there is an initiative in the United States that DNA samples should be disposed of after genetic testing of these samples. This hinders the effort to store and bank these samples for future use. Also, there is initiative that DNA used for research purposes should be disposed of shortly after its use. In essence, these legislative issues are being driven by the idea of insuring that an individual's genetic make-up be confidential if so desired.
Many individuals, companies, institutions rely on the collection and banking of one sample of genetic material for possible future use. Our process encourages that human genetic samples from several different body sites are collected for banking. For the following reasons and to take into account the following genetic contingencies, the collection of genetic material from several different human body sites for possible future use in genetic analysis or genetic testing represents an improvement over the collection of samples from one body site. There are different types of genetic mutations: germ line and somatic cell. It is likely that a germ line mutation would probably be present in most if not all of the cells of an individual's body. In this case, one DNA gene sample would probably give a fairly accurate account when that DNA was analyzed and tested for the genetic aberrance. A germline mutation occurs or is present in the egg or sperm which together form the zygote at the beginning of development. This is why most if not all of the cells would carry the genetic alteration being sought. Imprinting and other phenomenon may present exceptions. However, the somatic cell mutation or genetic alteration may happen during or after development. In effect then only cells that originate or come from that cell would carry the mutation and the body would show mosaicism. It may be then that a sample taken from one body site might not have come from the line of cells produced from the mutated somatic cell. In that event, the genetic alteration being sought would be missed if only that sample was available for testing. It would be better to have more than one genetic DNA sample available for testing to take into account this contingency or possibility. Our process and method helps to guard against these genetic variations. It is important to understand that as the zygote divides and fetal embryonic development begins, three embryonic germ layers of cells form: ectoderm, mesoderm, endoderm. Each of these embryonic layers gives rise to various tissues and organs. The ectoderm gives rise to epidermis, hair, brain, spinal column, sweat glands, certain parts of the eye, inner ear, epithelium of the nose/mouth/anus. The mesoderm gives rise to dermis, muscle, cartilage, bone, blood, connective tissue, blood vessels, reproductive organs, kidneys. The endoderm gives rise to the linings of the digestive tract and the respiratory tract, urethra, urinary bladder, gallbladder, liver, pancreas, thyroid, parathyroid, thymus. Genetic mutations leading to increased risk for certain diseases could be somatic and reside only in one or two of these three embryonic germ layers. Current technology allows us to compose and manufacture a multiple sample DNA collection kit which collects samples from the mouth cheek cells which are derived from ectoderm, hair follicles which are derived from ectoderm and mesoderm, and blood which is derived from mesoderm. As new developments, technology, and findings come about, our process is designed to include or substitute in our Kit a sample of some type of cell(s)/tissue(s) which is/are derived from endoderm. One possibility is to collect and store some type of sample such as urethral discharge, urine, urine sediment, urine filtrate (urine passed through a filter and the filtered material collected and stored) which may contain endoderm and/or mesoderm. Another possibility is to collect and store some type of material from the lining of the digestive tract which is derived from endoderm. Feces could possibly be dried, filtered, centrifuiged, or processed in some type of fashion suitable for DNA collection and storage/preservation. Another possibility is the collection of some type of respiratory tract material or secretion which contains endodermal material.
These additional ideas for collection of DNA for banking do not have to be limited to endodermal tissue. New discoveries in the future may make it possible for using better ways to collect and store DNA samples of mesodermal and ectodermal tissue/cells. Sorting out the phenomenon and influences of incomplete penetrance, variable expressivity, genetic-environmental interactions, inherited susceptibility mutations, acquired susceptibility mutations, baseline chance, imprinting, mosaicism, gene products, and others, most likely will require multiple cell samples from individuals and families. Likewise, diseases influenced by genetic factors can be affected through different mechanisms. Sometimes a disease or risk for a disease is influenced by Mendelian inheritance whereby a gene on a chromosome is the deciding factor. (Still, even in this case the germline versus somatic issue argues for multiple sample collection). On the other hand, sometimes a disease or risk for a disease is influenced by mutations or alterations of different genes on different chromosomes. This is called multifactorial. In the multifactorial scenario, the case of germnine versus somatic also exists. Let's look at the following hypothetical but realistic example which argues for multiple DNA sample collection. Mutation A, present on Chromosome #4, and Mutation B, present on Chromosome #7, contribute to increased risk to Disease X. Both must be present for the increased risk to occur. Mutation A is germnine so that it would be detected from a blood or mouth cheek cell DNA sample collected and stored. However, Mutation B is somatic cell and occurs only in progeny cells produced from the somatic cell first affected. For the sake of argument, let's say that blood cells are not part of the lineage arising from the somatic cell first affected with the Mutation B but cheek cells are part of the lineage. When blood cells from this individual were to be analyzed, Mutation A would be detected but not Mutation B. The genetic interpretation would be in error, inconclusive, or incomplete since both Mutation A and Mutation B would have to be detected to say that a person had increased susceptibility or risk to develop Disease X. In this case cheek cells would yield a more accurate interpretation.
If DNA from various body sources is found to vary even slightly, it could make a difference in the accuracy and efficiency of DNA genetic testing and diagnostic applications. There is also the possibility that genetic testing could be done with or is more effective and accurate with components associated with DNA, e.g. histones, proteins, glycoproteins, other gene products, ribose nucleic acid (RNA), etc. (At present the terminology for genetic material revolves around the usage of the words deoxyribose nucleic acid (DNA) and gene. This terminology may come to include other components which could be used in genetic analysis or genetic testing or genetic diagnosis. We are implying the collection of genetic material in its broadest sense, although we sometimes use the current accepted terminology involving DNA and genes.) It is possible that DNA in association with these components or in conjunction with these components allows for more accurate and efficient genetic testing and diagnosis. It may be that these associated products may be found in one body source but not another.